Starter: where are we?

1. Starter: where are we?

2. The sun is one of billions of stars in our galaxy, the Milky Way

3. Objectives • Learn the difference between a comet and an asteroid • Describe how stars are formed • Explain how the size of a star impacts the life cycle of a star

4. Comets and asteroids • Comets: have a frozen core of dust and gas. As they approach the sun the gases evaporate to form a tail making them easy to see • Asteroids: are a band of rock debris found between the orbits of Mars and Jupiter

5. The end... • Many small asteroids collide with Earth each year • Although the chances are small, it is predicted that an asteroid between 1-10km could hit the Earth within the next million years • This could create devastating tidal waves and so much dust could be released into the atmosphere that light is prevented from reaching the Earth

6. Twinkle, Twinkle, Little Star ...

7. How I wonder what you are! Stars are all at different stages of their life cycles. They do not last forever. Some of the stars we see no longer exist!

8. Star formation • Clouds of dust and gas called nebula are pulled together by strong gravitational forces • This increases the temperature and nuclear reactions start taking place • Massive amounts of energy are released and forms a star • Eventually the hydrogen gas runs out and the star gets colder and expands • What happens next depends on the size of the star

9. Put these stages of star formation in the correct order • Massive amounts of energy are released and forms a star • What happens next depends on the size of the star • Eventually the hydrogen gas runs out and the star gets colder and expands • Clouds of dust and gas called nebula are pulled together by strong gravitational forces • This increases the temperature and nuclear reactions start taking place

10. Check the order • Clouds of dust and gas called nebula are pulled together by strong gravitational forces • This increases the temperature and nuclear reactions start taking place • Massive amounts of energy are released and forms a star • Eventually the hydrogen gas runs out and the star gets colder and expands • What happens next depends on the size of the star

11. What happens next?If the star is about the size as the sun • The star cools and becomes a red giant • It continues to cool and then collapses under its own gravity to become a white dwarf • Eventually it becomes a black giant

12. What happens next?If the star is about the size as the sun • Label the flow chart

13. What happens next?If the star is about the size as the sun • Check your labels Star Red giant White dwarf Black dwarf

14. What happens next?If the star is much bigger than the sun • The star cools and becomes a red supergiant • It shrinks rapidly and explodes releasing energy dust and gas into space called a supernova • This dust and gas (nebula) forms new stars and the remains of the supernova will either be a neutron star or a black hole

15. What happens next?If the star is much bigger than the sun • Label the flowchart

16. What happens next?If the star is much bigger than the sun • Check your labels Neutron star Supernova Star Red supergiant Black hole